<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="root"></div>

    <script
      src="https://unpkg.com/react@18/umd/react.development.js"
      crossorigin
    ></script>
    <script
      src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"
      crossorigin
    ></script>
    <script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>

    <script type="text/babel">
      const root = ReactDOM.createRoot(document.querySelector('#root'))

      class App extends React.Component {
        constructor() {
          super()

          this.state = {
            isShow: true
          }
        }

        changeShow() {
          this.setState({
            isShow: !this.state.isShow
          })
        }

        render() {
          const { isShow } = this.state

          const showContent = isShow ? 'block' : 'none'

          return (
            <div>
              <button onClick={() => this.changeShow()}>切换</button>

              {isShow && <h2>哈哈哈</h2>}

              <h2 style={{ display: showContent }}>哈哈哈</h2>
            </div>
          )
        }
      }

      root.render(<App />)
    </script>
  </body>
</html>
